1. Field of the Invention
The invention relates to a stereoscopic display apparatus for supplying right and left two images with a difference between visual angles of both eyes to stereoscopic image display means, thereby stereoscopically displaying the images by the stereoscopic image display means.
2. Description of Background Information
A system for stereoscopically displaying an image can be mainly classified into two kinds of a multi-eye type stereoscopic video system and a double-eye type stereoscopic video system.
The multi-eye type stereoscopic video system is disclosed in, for example, Japanese Patent Kokai (laying open) Nos. 6-269025, 4-344795, and 6-148763.
FIG. 1 shows an example of a stereoscopic display apparatus using this multi-eye type stereoscopic video system.
As shown in FIG. 1, a camera group 2 comprising four cameras 2a to 2d is arranged so that a distance between the adjacent cameras is generally equal to an interval between human eyes, and the camera group 2 shoots a dice 1 as an object. Video signals of the dice 1 taken by the cameras 2a to 2d are regularly supplied to a video image display apparatus 3 (for example, liquid crystal display apparatus) in accordance with the order of arrangement of the cameras, respectively. A solid video image of the dice 1 is observed from the front side of a lenticular lens 4.
For example, video images seen by an observer 5 from a front position 5a are video images taken by the cameras 2a and 2b and the dice 1 is observed as a stereoscopic image like an image 6a. The video images seen by the observer 5 who has moved to a position 5b on the left-hand side are video images taken by the cameras 2a and 2c and the dice 1 is observed as a stereoscopic image like an image 6b. Similarly, when the observer 5 moves to a position 5c on the right side, a stereoscopic image 6c of the dice 1 which is obtained from the cameras 2b and 2d is observed.
As mentioned above, in the case of the multi-eye type image display apparatus, when the observer 5 moves along the video image display apparatus in front of the apparatus, the observer sees the video images taken at a position that is equivalent to the position where he has moved. The observer, consequently, can see the video image as if he observed a real image of the object.
The stereoscopic video system has been disclosed in, for example, Japanese Patent Kokoku No. 6-34528 and Japanese Patent Kokai No. 61-23116. FIG. 2 shows a stereoscopic display apparatus using the double-eye type stereoscopic video system. Video signals obtained by shooting the dice 1 by the left and right two cameras 2a and 2b can be observed by using the video image display apparatus 3.
According to the stereoscopic display apparatus of the multi-eye type, although the object can be displayed on a screen as a natural form, the apparatus increases in size and becomes complicated and the range of its uses is limited in spite that there is an effective use value in such fields as the product development and education using a stereoscopic image.
According to the double-eye type, as shown in FIG. 2, since the video signals obtained by the two cameras 2a and 2b arranged for the left and right eyes are merely observed by two eyes, although the dice 1 can be observed as a solid video image, even if the observer 5 moves to the left side 5b, front 5a, and right side 5c in front of the video image display apparatus 3, only the video image 6a observed at the (front) position 5a is always obtained as a video image that is derived from the video image display apparatus 3. More particularly, the video images 6b and 6c which are obtained by the multi-eye type as shown in FIG. 1 cannot be obtained. As mentioned above, according to the double-eye type, although the object can be observed as a stereoscopic image, it is limited to a range of the stereoscopic video images obtained by shooting the object by two cameras. A video image corresponding to the movement of the viewing point position in association with the motion of the face of the observer or the movement of the observer as in the case of the multi-eye type cannot be obtained.
Therefore, although it is sufficient to use the double-eye type image display apparatus for images if it is targeted to merely stereoscopically observe the object as in the case of a scenery, a flower garden, or the like, a desired target cannot be accomplished with the double-eye type image display apparatus as in the case of an application such that an automobile is examined as a solid structure that is seen from many positions of different viewing angles, and the like situations.